On Thu, 2023-03-02 at 17:09 -0600, Chris Adams wrote:
Lots of the time, UPSes and generators are not actively monitored and tested. An untested backup system is not a backup system, it's just another point of failure! I have seen failures of big UPSes, generators, transfer switches... you name it, even if it is "redundant", it can (and will) still fail.
I have a UPS sitting next to me, right now, in pieces, which (half) died in a most peculiar manner:
A burning smell was eventually traced to it. There's no visible signs of burning, and no schematic available for the model, that I can find. A rather acrid smell, not one I'm used to with component failure, I'm beginning to suspect a large AC transformer.
While running off the mains its output is a (too) low voltage, but still high enough for most switch-mode power supplies to run normally (i.e. the computer and monitor). It has some kind of AC voltage regulation built into it to deal with under and over-voltage. The AC supply was normal, at the time.
But running off its battery it produces the full 240 volts it's supposed to.